Nesfatin-1 and nesfatin-1-like peptide attenuate hepatocyte lipid accumulation and nucleobindin-1 disruption modulates lipid metabolic pathways

Nesfatin-1 (NESF-1) has been shown to modulate lipid metabolism. We have identified a nesfatin-1-like-peptide (NLP) processed from a related precursor nucleobindin 1 (NUCB1). Here we determined if NLP, like NESF-1, regulates lipid accumulation in vitro, and tested if the disruption of nucb1 gene affects hepatic lipid metabolism genes in mice. Hepatocytes (HepG2/C3A cells) express NLP and NESF-1 and both peptides significantly reduced lipogenic enzyme mRNAs and enhanced beta-oxidation enzyme mRNAs. Lipid contents in oleic acid induced HepG2/C3A cells were attenuated by NESF-1 and NLP. The inhibitory effect on cellular lipid content was blocked by compound C, an inhibitor of AMPK. The disruption of nucb1 gene affected lipid metabolism-related enzyme mRNAs, endogenous nucb2 mRNA and AMPK phosphorylation. The lipid-lowering effects identified here highlights the potential of nucleobindins and peptides processed from them to address lipid disorders, and its possible benefits in metabolic disease management.

Nucleobindin-2 derived nesfatin-1 in polycystic ovary syndrome: a PRISMA and GRADE-compliant systematic review and meta-analysis with diagnostic test accuracy

INTRODUCTION

Nesfatin-1 is a satiety peptide secreted by central, peripheral nervous system and some peripheral tissues. This meta-analysis was conducted to explore the associations with diagnostic accuracy of circulatory nesfatin-1 in polycystic ovary syndrome (PCOS).

EVIDENCE ACQUISITION

Relevant studies were retrieved by online database and manual searching. The standardized mean differences (SMDs) with 95% confidence intervals (CIs) were obtained by a random-effects meta-analysis. The subgroup analysis based on the Body Mass Index (BMI), fasting insulin (F-INS), and the homeostasis model assessment-estimated insulin resistance (HOMA-IR) was conducted. Meta-analysis of correlations and meta-regression were performed for the associations of nesfatin-1 with metabolic and hormonal covariates. The diagnostic test accuracy (DTA) meta-analysis was conducted for the utility of nesfatin-1 in PCOS. The publication bias was tested with Egger's and Begg's regression tests.

EVIDENCE SYNTHESIS

The combined effect size including a total of 14 studies showed a significantly higher nesfatin-1 level in PCOS as compared to controls (SMD=0.93, Z=2.17, P=0.03). The nesfatin-1 was found to be significantly higher in a subgroup of studies with mean BMI>25 kg/m2 (SMD=1.35, Z=2.06, P=0.04), F-INS <13 mIU/mL (SMD=2.74, Z=3.59, P=0.0003), and HOMA-IR >2.7 (SMD=1.58, Z=2.65, P=0.008). The DTA meta-analysis produced a pooled diagnostic odds ratio of 19.58 and area under curve were of 0.888 for nesfatin-1 in PCOS.

CONCLUSIONS

The results indicate a multifactorial involvement such as endocrine and metabolic alterations in the form of BMI, insulin and HOMA-IR status with the higher nesfatin-1 levels in PCOS. The promising results of DTA meta-analysis warrants further research into the clinical and prognostic utility of nesfatin-1 in PCOS.

Ovarian nesfatin-1 in Hemidactylus flaviviridis: Reproductive phase-dependent expression, role and hormonal regulation

Nesfatin-1 has recently emerged as a modulator of ovarian functions in mammals. Studies in non-mammalian vertebrates, though limited and majorly restricted to fishes, have evidenced a role of this peptide in the regulation of ovarian steroidogenesis and oocyte maturation. Interestingly, nesfatin-1 remains completely unexplored in reptiles. Therefore, the present study aimed to identify nesfatin-1 and elucidate its role and regulation in the ovary of Hemidactylus flaviviridis. Ovarian expression of nucb2/nesfatin-1 was highest during late recrudescence and breeding while it was lowest during regression. Follicular stage-dependent expression analysis showed significantly high expression of nucb2/nesfatin-1 in previtellogenic follicles. Further, in vitro treatment of recrudescent wall lizard ovaries with nesfatin-1 resulted in increased expression of anti-apoptotic gene, bcl-2, along with a concomitant decline in the pro-apoptotic gene, caspase-3. In addition, proliferation/differentiation markers like scf, c-kit, pcna, and bmp-15 were stimulated in ovaries incubated with the peptide. Ovarian steroidogenesis was also positively influenced by nesfatin-1 as treatment with the peptide resulted in heightened star expression as well as increased estradiol and progesterone production. Also, all concentrations of nesfatin-1 stimulated glucose uptake and metabolism in wall lizard ovary. Our observations provide the first evidence of ovarian functions of nesfatin-1 in a reptile. Further, ovarian nucb2/nesfatin-1 was differentially regulated by gonadotropin and sex steroids wherein its expression was stimulated by dihydrotestosterone (DHT) and 17β-estradiol (E2) but inhibited by follicle-stimulating hormone (FSH). In summary, this is the first report of the presence, reproductive stage-dependent expression, role, and regulation of ovarian nucb2/nesfatin-1 in H. flaviviridis.

Effects of physical activity and exercise on Nucleobindin-2 gene expression and Nesfatin-1 concentration: A rapid review

The aim of this rapid review is to examine the research evidence that presents the effects of physical activity and exercise on Nucleobindin-2 (NUCB2) gene expression and Nesfatin-1 concentration. Five databases (PubMed, Science Direct, Springer, Wiley, and Google Scholar) were searched for eligible studies from the earliest available date to August 2023. In human studies, Nesfatin-1 concentration either remains unchanged or increases after exercise training. It appears that higher exercise intensity and longer duration of training accentuate the increase of blood Nesfatin-1 concentration. The few human studies that have examined the acute response of exercise on Nesfatin-1 concentration from blood draws show conflicting results. There is a severe lack of biopsy studies in humans which warrants attention. All published animal studies have used the mouse model. The majority show that regular exercise training increases tissue NUCB2/Nesfatin-1. In some animal studies, where the effects of exercise on tissue Nesfatin-1 concentration has been seen as significant, there has been no significant effect of exercise on plasma Nesfatin-1 concentration. All animal studies evaluated the effect of endurance training except one which used resistance training. No animal studies have investigated the effects of acute exercise, which warrants investigation. In conclusion, human and animal studies have shown that physical training can increase NUCB2/Nesfatin-1, but research evidence examining the effect of acute exercise is in its infancy. In addition, future comparative studies are needed to compare the effects of different training protocols on NUCB2/Nesfatin-1 in humans and animals.

Alterations in Appetite-Regulating Hormones in Girls with Central Early or Precocious Puberty

The prevalence of central precocious puberty (CPP) in girls has increased worldwide and is often associated with obesity in childhood as well as high fat/high glycemic index diets. Evidence suggests that subjects with obesity present with alterations in appetite-regulating hormones. The arcuate and paraventricular nuclei of the hypothalamus are the centers of action of appetite hormones, as well as the location of gonadotropin-releasing hormone (GnRH) neurons, the activation of which results in the onset of puberty. This anatomical proximity raises the question of possible alterations in appetite-regulating hormones in patients with CPP. Furthermore, diet-induced hypothalamic inflammation constitutes a probable mechanism of the pathophysiology of CPP, as well as alterations in appetite-regulating hormones in young children. In this article, we summarize the evidence investigating whether girls with CPP present with alterations in appetite-regulating hormones. We present evidence that leptin concentrations are elevated in girls with CPP, ghrelin concentrations are lower in girls with CPP, nesfatin-1 and orexin-A concentrations are elevated among girls with premature thelarche, and insulin concentrations are increased in girls with early menarche.

Nesfatin-1 regulates steroidogenesis in mouse Leydig cells

Nesfatin-1 is a polypeptide hormone known to regulate appetite and energy metabolism and is derived from the precursor protein nucleobindin 2 (NUCB2). Recent studies have shown that nesfatin-1 is expressed in many peripheral tissues in mice, including the reproductive organs. However, its function and regulation in the testis remain unknown. In this study, we investigated the expression of Nucb2 mRNA and nesfatin-1 protein in mouse Leydig cells and the Leydig cell line, TH3 cells. We also examined whether Nucb2 mRNA expression is regulated by gonadotropins and whether exogenous nesfatin-1 affects steroidogenesis in primary Leydig cells isolated from testis and TH3 cells. We found that Nucb2 mRNA and nesfatin-1 protein were present in primary Leydig cells and TM3 cells, and nesfatin-1 binding sites were also found in both cell types. Nucb2 mRNA expression in testis, primary Leydig cells, and TM3 cells was increased after treatment with pregnant mare's serum gonadotropin and human chorionic gonadotropin. After nesfatin-1 treatment, the expression of steroidogenesis-related enzyme genes Cyp17a1 and Hsd3b was upregulated in primary Leydig cells and TM3 cells. Our results suggest that NUCB2/nesfatin-1 expression in mouse Leydig cells may be regulated through the hypothalamic-pituitary-gonadal axis and that nesfatin-1 produced by Leydig cells may locally regulate steroidogenesis in an autocrine manner. This study provides insight into the regulation of NUCB2/nesfatin-1 expression in Leydig cells and the effect of nesfatin-1 on steroidogenesis, which may have implications for male reproductive health.

Tissue-Specific Modulation of Gluco- and Growth-Regulatory Factor Abundance by Nesfatin-1 and Nesfatin-1-like Peptide in Goldfish

Nesfatin-1 and nesfatin-1-like peptide (Nlp) are derived from precursors nucleobindin-2 and -1, two calcium and DNA binding proteins, respectively. Both peptides exhibit hormone-like actions in mammals and fish. These functions include insulinotropic effects of nesfatin-1 and Nlp seen in mice and their growth hormone suppressive actions reported in goldfish. We hypothesized that nesfatin-1 and Nlp are insulin stimulatory (in adipose tissue) and modulate growth hormone and insulin-like growth factors and glucose transporters in goldfish. To test this, goldfish were intraperitoneally injected with either nesfatin-1 or Nlp (50 ng/g BW) or saline alone (control) and sampled at one-hour post-injection (in vivo study). In a separate study, tissue samples were collected and were incubated with either nesfatin-1 or Nlp for one or six hours (in vitro study). Transcript (mRNA) abundance data from the adipose tissue suggest that both nesfatin-1 and Nlp significantly upregulate the abundance of preproinsulin, insulin receptors, and pcsk1 and pcsk2 mRNAs. Meanwhile, the abundance of preproglucagon mRNA in the adipose tissue was significantly downregulated in both in vivo and in vitro studies. These results agree with the insulinotropic and glucagonostatic roles for nesfatin-1 and Nlp reported in rodents. The transcript abundance of growth regulators (igf1, igf2a, and ghra) and glucose transporters (slc2a2 and slc5a1) were upregulated in the muscle, while an opposite effect on these mRNAs was found in the liver of goldfish following nesfatin-1 and Nlp administration. Our results suggest that both nesfatin-1 and Nlp have tissue-specific regulatory roles on growth and glucoregulatory elements in the liver and muscle of goldfish. This agrees with our previous studies that showed a suppressive action of nesfatin-1 on growth hormone in goldfish liver. The results presented here provide strong supportive/confirmatory evidence for tissue-specific insulinotropic and gluco- and growth-regulatory actions of nesfatin-1 and Nlp in goldfish.

Unravelling the neuropeptidome of the ornate spiny lobster Panulirus ornatus: A focus on peptide hormones and their processing enzymes expressed in the reproductive tissues

Neuropeptides are commonly produced in the neural tissues yet can have effects on far-reaching targets, with varied biological responses. We describe here the neuropeptidome of the ornate spiny lobster, Panulirus ornatus, a species of emerging importance to closed-system aquaculture, with a focus on peptide hormones produced by the reproductive tissues. Transcripts for a precursor to one neuropeptide, adipokinetic hormone/corazonin-related peptide (ACP) were identified in high numbers in the sperm duct of adult spiny lobsters suggesting a role for ACP in the reproduction of this species. Neuropeptide production in the sperm duct may be linked with physiological control of spermatophore production in the male, or alternatively may function in signalling to the female. The enzymes which process nascent neuropeptide precursors into their mature, active forms have seldom been studied in decapods, and never before at the multi-tissue level. We have identified transcripts for multiple members of the proprotein convertase subtisilin/kexin family in the ornate spiny lobster, with some enzymes showing specificity to certain tissues. In addition, other enzyme transcripts involved with neuropeptide processing are identified along with their tissue and life stage expression patterns.

Neuropeptides as regulators of the hypothalamus-pituitary-gonadal (HPG) axis activity and their putative roles in stress-induced fertility disorders

Neuropeptides being regulators of the hypothalamus-pituitary-adrenal (HPA) axis activity, also affect the function of the hypothalamus-pituitary-gonadal (HPG) axis by regulating gonadotrophin-releasing hormone (GnRH) secretion from hypothalamic neurons. Here, we review the available data on how neuropeptides affect HPG axis activity directly or indirectly via their influence on the HPA axis. The putative role of neuropeptides in stress-induced infertility, such as polycystic ovary syndrome, is also described. This review discusses both well-known neuropeptides (i.e., kisspeptin, Kp; oxytocin, OT; arginine-vasopressin, AVP) and more recently discovered peptides (i.e., relaxin-3, RLN-3; nesfatin-1, NEFA; phoenixin, PNX; spexin, SPX). For the first time, we present an up-to-date review of all published data regarding interactions between the aforementioned neuropeptide systems. The reviewed literature suggest new pathophysiological mechanisms leading to fertility disturbances that are induced by stress.

Neuroendocrine Control of Reproduction in Teleost Fish: Concepts and Controversies

During the teleost radiation, extensive development of the direct innervation mode of hypothalamo-pituitary communication was accompanied by loss of the median eminence typical of mammals. Cells secreting follicle-stimulating hormone and luteinizing hormone cells are directly innervated, distinct populations in the anterior pituitary. So far, ∼20 stimulatory and ∼10 inhibitory neuropeptides, 3 amines, and 3 amino acid neurotransmitters are implicated in the control of reproduction. Positive and negative sex steroid feedback loops operate in both sexes. Gene mutation models in zebrafish and medaka now challenge our general understanding of vertebrate neuropeptidergic control. New reproductive neuropeptides are emerging. These include but are not limited to nesfatin 1, neurokinin B, and the secretoneurins. A generalized model for the neuroendocrine control of reproduction is proposed. Hopefully, this will serve as a research framework on diverse species to help explain the evolution of neuroendocrine control and lead to the discovery of new hormones with novel applications. Expected final online publication date for the Annual Review of Animal Biosciences, Volume 10 is February 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Nesfatin-1-like peptide is a negative regulator of cardiovascular functions in zebrafish and goldfish

Nucleobindins (NUCB1 and NUCB2) were originally identified as calcium and DNA binding proteins. Nesfatin-1 (NEFA/nucleobindin-2-Encoded Satiety and Fat-Influencing proteiN-1) is an 82 amino acid anorexigenic peptide encoded in the N-terminal region of NUCB2. We have shown that nesfatin-1 is a cardiosuppressor in zebrafish. Both NUCB1 and NUCB2 possess a -very highly conserved bioactive core. It was found that a nesfatin-1-like peptide (NLP) encoded in NUCB1 suppresses food intake in fish. In this research, we investigated whether NLP has nesfatin-1-like effects on cardiovascular functions. NUCB1/NLP-like immunoreactivity was found in the atrium and ventricle of the heart and skeletal muscle of zebrafish. Intraperitoneal injection (IP) of either zebrafish NLP or rat NLP suppressed cardiac functions in both zebrafish and goldfish. Irisin and RyR1b mRNA expression was downregulated by NLP in zebrafish cardiac and skeletal muscles. However, cardiac ATP2a2 mRNA expression was elevated after NLP injection. Administration of scrambled NLP did not affect irisin, RyR1b or ATP2a2 mRNA expression in zebrafish. Together, these results implicate NLP as a suppressor of cardiovascular physiology in zebrafish and goldfish.

The Role of the Gastric Hormones Ghrelin and Nesfatin-1 in Reproduction

Ghrelin and nesfatin-1 are enteroendocrine peptide hormones expressed in rat X/A-like and human P/D1cells of the gastric mucosa. Besides their effect on food intake, both peptides are also implicated in various other physiological systems. One of these is the reproductive system. This present review illustrates the distribution of ghrelin and nesfatin-1 along the hypothalamus–pituitary–gonadal (HPG) axis, their modulation by reproductive hormones, and effects on reproductive functions as well as highlighting gaps in current knowledge to foster further research.

The Role of the Gastric Hormones Ghrelin and Nesfatin-1 in Reproduction

Ghrelin and nesfatin-1 are enteroendocrine peptide hormones expressed in rat X/A-like and human P/D1cells of the gastric mucosa. Besides their effect on food intake, both peptides are also implicated in various other physiological systems. One of these is the reproductive system. This present review illustrates the distribution of ghrelin and nesfatin-1 along the hypothalamus-pituitary-gonadal (HPG) axis, their modulation by reproductive hormones, and effects on reproductive functions as well as highlighting gaps in current knowledge to foster further research.

The Role of the Gastric Hormones Ghrelin and Nesfatin-1 in Reproduction

Ghrelin and nesfatin-1 are enteroendocrine peptide hormones expressed in rat X/A-like and human P/D1cells of the gastric mucosa. Besides their effect on food intake, both peptides are also implicated in various other physiological systems. One of these is the reproductive system. This present review illustrates the distribution of ghrelin and nesfatin-1 along the hypothalamus–pituitary–gonadal (HPG) axis, their modulation by reproductive hormones, and effects on reproductive functions as well as highlighting gaps in current knowledge to foster further research.

Nesfatin-1 stimulates the hypothalamus-pituitary-interrenal axis hormones in goldfish

Stress in vertebrates is mediated by the hypothalamus-pituitary-adrenal (in mammals)/interrenal (in fish) (HPA/I) axis, which produces the corticotropin-releasing factor (CRF), adrenocorticotropic hormone (ACTH), and corticosteroids, respectively. Nesfatin-1, a novel anorexigenic peptide encoded in the precursor nucleobindin-2 (NUCB2), is increasingly acknowledged as a peptide that influences the stress axis in mammals. The primary aim of this study was to characterize the putative effects of nesfatin-1 on the fish HPI axis, using goldfish (Carassius auratus) as an animal model. Our results demonstrated that nucb2/nesfatin-1 transcript abundance was detected in the HPI tissues of goldfish, with most abundant expression in the pituitary. NUCB2/nesfatin-1-like immunoreactivity was found in the goldfish hypothalamus, pituitary, and interrenal cells of the head kidney. GPCR12, a putative receptor for nesfatin-1, was also detected in the pituitary and interrenal cells. NUCB2/nesfatin-1-like immunoreactivity was observed in ACTH-expressing pituitary corticotrophs. Acute netting and restraint stress upregulated nucb2/nesfatin-1 mRNA levels in the forebrain, hypothalamus, and pituitary, as well as crf and crf-r1 expression in the forebrain and hypothalamus. Intraperitoneal and intracerebroventricular administration of nesfatin-1 increased cortisol release and hypothalamic crf mRNA levels, respectively. Finally, we found that nesfatin-1 significantly stimulated ACTH secretion from dispersed pituitary cells in vitro. Collectively, our data provide the first evidence showing that nesfatin-1 is a stress responsive peptide, which modulates the stress axis hormones in fish.

A comparative account of nesfatin-1 in vertebrates

Nesfatin-1 was discovered as an anorexigenic peptide derived from proteolytic cleavage of the prepropeptide, nucleobindin 2 (NUCB2). It is widely expressed in central as well as peripheral tissues and is known to have pleiotropic effects such as regulation of feeding, reproduction, cardiovascular functions and maintenance of glucose homeostasis. In order to execute its multifaceted role, nesfatin-1 employs diverse signaling pathways though its receptor has not been identified till date. Further, nesfatin-1 is reported to be under the regulatory effect of feeding state, nutritional status as well as several metabolic and reproductive hormones. This peptide has also been associated with variety of human diseases, especially metabolic, reproductive, cardiovascular and mental disorders. The current review is aimed to present a consolidated picture and highlight lacunae for further investigation in order to develop a deeper comprehensive understanding on physiological significance of nesfatin-1 in vertebrates.

Nesfatin-1 is an inhibitor of the growth hormone-insulin-like growth factor axis in goldfish (Carassius auratus)

Nesfatin-1, an 82 amino acid peptide cleaved from the N-terminal of its precursor nucleobindin-2 (NUCB2), is emerging as a multifunctional peptide in fish. The present study aimed to determine whether nesfatin-1 plays a role in fish somatic growth by modulating the growth hormone (GH)/insulin-like growth factor (IGF) axis, using a representative teleost model, the goldfish (Carassius auratus). The results demonstrated that a single i.p. injection of synthetic goldfish nesfatin-1 significantly decreased the expression of hypothalamic pacap (approximately 90%) and pituitary Gh (approximately 90%) mRNAs at 15 minutes post-injection. Serum GH levels were also reduced as a result of nesfatin-1 administration, by approximately 45% and 55% at 15 and 30 minutes post-injection, respectively. Likewise, in vitro treatment of goldfish dispersed pituitary cells with nesfatin-1 reduced Gh secretion, suggesting that nesfatin-1 acts directly on pituitary somatotrophs to inhibit Gh release. Exposure of cultured liver fragments to nesfatin-1 (0.1, 1 and 10 nmol L^-1 ) led to a significant reduction in igf-1 mRNA at 120 minutes and of igf-II mRNA at 30 and 60 minutes post-incubation. Collectively, these results indicate a suppressive role for nesfatin-1 on the goldfish GH/IGF axis. Immunohistochemical studies demonstrated that NUCB2/nesfatin-1-like immunoreactivity, although present in the goldfish pituitary, is not colocalised with GH in goldfish somatotrophs. Thus, nesfatin-1 does not appear to act in an autocrine manner to regulate GH secretion. Taken together, this research found that the pituitary gland is an important source of endogenous NUCB2/nesfatin-1 and also that nesfatin-1 directly suppresses the Gh/IGF axis in goldfish.

Transcriptome Profiling of the Pacific Oyster Crassostrea gigas Visceral Ganglia over a Reproduction Cycle Identifies Novel Regulatory Peptides

The neuropeptides involved in the regulation of reproduction in the Pacific oyster (Crassostrea gigas) are quite diverse. To investigate this diversity, a transcriptomic survey of the visceral ganglia (VG) was carried out over an annual reproductive cycle. RNA-seq data from 26 samples corresponding to VG at different stages of reproduction were de novo assembled to generate a specific reference transcriptome of the oyster nervous system and used to identify differentially expressed transcripts. Transcriptome mining led to the identification of novel neuropeptide precursors (NPPs) related to the bilaterian Eclosion Hormone (EH), crustacean female sex hormone/Interleukin 17, Nesfatin, neuroparsin/IGFBP, prokineticins, and urotensin I; to the protostome GNQQN, pleurin, prohormones 3 and 4, prothoracotropic hormones (PTTH), and QSamide/PXXXamide; to the lophotrochozoan CCWamide, CLCCY, HFAamide, and LXRX; and to the mollusk-specific NPPs CCCGS, clionin, FYFY, GNamide, GRWRN, GSWN, GWE, IWMPxxGYxx, LXRYamide, RTLFamide, SLRFamide, and WGAGamide. Among the complete repertoire of NPPs, no sex-biased expression was observed. However, 25 NPPs displayed reproduction stage-specific expression, supporting their involvement in the control of gametogenesis or associated metabolisms.

Neuroendocrine Peptides of the Gut and Their Role in the Regulation of Food Intake

The regulation of food intake encompasses complex interplays between the gut and the brain. Among them, the gastrointestinal tract releases different peptides that communicate the metabolic state to specific nuclei in the hindbrain and the hypothalamus. The present overview gives emphasis on seven peptides that are produced by and secreted from specialized enteroendocrine cells along the gastrointestinal tract in relation with the nutritional status. These established modulators of feeding are ghrelin and nesfatin-1 secreted from gastric X/A-like cells, cholecystokinin (CCK) secreted from duodenal I-cells, glucagon-like peptide 1 (GLP-1), oxyntomodulin, and peptide YY (PYY) secreted from intestinal L-cells and uroguanylin (UGN) released from enterochromaffin (EC) cells. © 2021 American Physiological Society. Compr Physiol 11:1679-1730, 2021.

Nesfatin-1 and nesfatin-1-like peptide suppress growth hormone synthesis via the AC/PKA/CREB pathway in mammalian somatotrophs

Nesfatin-1 (NESF) and NESF-like peptide (NLP), encoded in nucleobindin 2 and 1 (NUCB2 and NUCB1), respectively, are orphan ligands and metabolic factors. We hypothesized that NESF and NLP suppress growth hormone (GH) synthesis, and aimed to determine whether mammalian somatotrophs are a source and site of action of these peptides. Using immortalized rat somatotrophs (GH3 cells), NUCB expression was determined by qPCR, immunofluorescence and Western blot. NESF and NLP binding to GH3 cells was tested using fluorescence imaging. Both time- and concentration-dependent studies were performed to test whether NESF and NLP affect GH. Moreover, the ability of these peptides to modulate the effects of ghrelin, and cell-signaling pathways were studied. GH3 cells express NUCB mRNAs and protein. Labeled NESF and NLP bind to the surface of GH3 cells, and incubation with either NESF or NLP decreased GH mRNA and protein expression, downregulated pit-1 mRNA, and blocked the GH stimulatory effects of ghrelin. Pre-incubation with either of these peptides reduced CREB phosphorylation by an AC-activator, but not when PKA was directly activated by a cAMP analog. Our results indicate that rat somatotrophs are a source of NUCBs, and that NESF and NLP downregulate GH synthesis through the AC/PKA/CREB signaling pathway.

Antioxidant, Anti-Inflammatory and Anti-Apoptotic Activities of Nesfatin-1: A Review

Nesfatin-1, a newly identified energy-regulating peptide, is widely expressed in the central and peripheral tissues, and has a variety of physiological activities. A large number of recent studies have shown that nesfatin-1 exhibits antioxidant, anti-inflammatory, and anti-apoptotic properties and is involved in the occurrence and progression of various diseases. This review summarizes current data focusing on the therapeutic effects of nesfatin-1 under different pathophysiological conditions and the mechanisms underlying its antioxidant, anti-inflammatory, and anti-apoptotic activities.

Neural remodelling in spiny lobster larvae is characterized by broad neuropeptide suppression

Neuropeptides are ancient endocrine components which have evolved to regulate many aspects of biology across the animal kingdom including behaviour, development and metabolism. To supplement current knowledge, we have utilized a transcriptome series describing larval development in the ornate spiny lobster, Panulirus ornatus. The biology of this animal has been leveraged to provide insights into the roles of molting, metamorphosis and metabolism across the neuropeptide family. We report an extensive list of neuropeptides across three distinct life phases of the animal. We show distinct groups of neuropeptides with differential expression between larval phases, indicating phase-specific roles for these peptides. For selected neuropeptides, we describe and discuss expression profiles throughout larval development and report predicted peptide cleavage sites and mature peptide sequences. We also report the neuropeptide nesfatin for the first time in a crustacean, and report secondary peptide products with a level of evolutionary conservation similar to the conventional mature peptide nesfatin-1, indicating a conserved role in these secondary products which are widely regarded as biologically inactive. In addition, we report a trend of downregulation in the neuropeptides as the animal undergoes extensive neural remodelling in fulfillment of metamorphosis. We suggest that this downregulation in neuropeptides relates to the brief, yet dramatic changes in morphology experienced by the central nervous system in the process of metamorphosis.

Serum nesfatin-1 is associated with testosterone and the severity of erectile dysfunction

This cross-sectional study aimed to evaluate serum nesfatin-1 concentrations in patients with erectile dysfunction (ED). Patients with ED were selected from the Department of Urology of the Second Affiliated Hospital of Anhui Medical University. The International Index of Erectile Function-5 (IIEF-5) was used to evaluate the severity of ED. Serum nesfatin-1 and gonadal hormone levels, including luteinising hormone (LH), follicle-stimulating hormone (FSH) and testosterone were measured. The IIEF-5 scores (t = -21.034, p < .001) and nesfatin-1 levels (t = -7.043, p < .001) in patients with ED were significantly lower than in healthy controls. Moreover, patients with ED showed decreased testosterone levels (t = -3.478, p = .001), whereas there were no significant differences in serum levels of FSH (t = -0.088, p = .930) and LH (t = 1.114, p = .270) between the two groups. Furthermore, positive relationships were found between serum nesfatin-1 and testosterone concentrations (r = .742, p = .001) and IIEF-5 scores (r = .395, p = .009) in ED patients. Additionally, based on receiver operating characteristic curve analysis, the area under curve for nesfatin-1 was 0.884 with 83.3% sensitivity and 81.4% specificity in discriminating ED patients from healthy controls. The decrease in serum nesfatin-1 level may be related to testosterone and the severity of ED.

Nesfatin-1-like peptide suppresses hypothalamo-pituitary-gonadal mRNAs, gonadal steroidogenesis, and oocyte maturation in fish†

Nucleobindin (Nucb)-1 and Nucb2 are DNA and Ca2+ binding proteins with multiple functions in vertebrates. Prohormone convertase-mediated processing of Nucb2 results in the production of biologically active nesfatin-1. Nesfatin-1 is involved in the regulation of reproduction in many vertebrates, including fish. Our lab originally reported a nesfatin-1-like peptide (Nlp) encoded in Nucb1 that exhibits nesfatin-1-like metabolic effects. We hypothesized that Nlp has a suppressive role in the reproductive physiology of fish. In this research, whether Nlp regulates reproductive hormones and oocyte maturation in fish were determined. Single intraperitoneal (IP) injection of goldfish Nlp (50 ng/g body weight) suppressed salmon and chicken gonadotropin-releasing hormone (sgnrh and cgnrh2), gonadotropin-inhibiting hormone (gnih) and its receptor (gnihr), and kisspeptin and brain aromatase mRNA expression in the hypothalamus of both male and female goldfish. In the pituitary, Nlp decreased mRNAs encoding lhb, fshb and kisspeptin and its receptor, while a significant increase in gnih and gnihr was observed. In the gonads, lh (only in male fish) and fsh receptor mRNAs were also significantly downregulated in Nlp-injected fish. Sex-specific modulation of gnih, gnihr, and kisspeptin system in the gonads was also observed. Nlp decreased sex steroidogenic enzyme encoding mRNAs and circulating levels of testosterone and estradiol. In addition, incubation of zebrafish ovarian follicles with Nlp resulted in a reduction in oocyte maturation. These results provide evidence for a robust role for Nlp in regulating reproductive hormones in goldfish and oocyte maturation in zebrafish, and these effects resemble that of nesfatin-1.

NUCB2/nesfatin-1 - Inhibitory effects on food intake, body weight and metabolism

Since its discovery in 2006 by Oh-I and colleagues, NUCB2/nesfatin-1 encoded by nucleobindin-2 (NUCB2) has drawn sustained attention as reflected in over 500 publications. Among those, more than half focused on the alterations of food intake, body weight and metabolism (glucose, fat) induced by nesfatin-1 and/or NUCB2/nesfatin-1. In the current review we discuss the existing literature focusing on NUCB2/nesfatin-1's influence on food intake, body weight and glucose as well as fat metabolism and highlight gaps in knowledge.

Phoenixin-20 Stimulates mRNAs Encoding Hypothalamo-Pituitary-Gonadal Hormones, is Pro-Vitellogenic, and Promotes Oocyte Maturation in Zebrafish

Phoenixin-20 (PNX-20) is a bioactive peptide with hormone-like actions in vertebrates. In mammals, PNX stimulates hypothalamo-pituitary-gonadal hormones and regulate reproductive processes. Our immunohisto/cytochemical studies show PNX-like and the putative PNX receptor, SREB3-like immunoreactivity in the gonads of zebrafish, and in zebrafish liver (ZFL) cells. Intraperitoneal injection of zebrafish PNX-20 upregulates mRNAs encoding both salmon gonadotropin-releasing hormone (GnRH), and chicken GnRH-II and kisspeptin and its receptor in zebrafish hypothalamus. Similarly, luteinizing hormone receptor mRNA expression in the testis, follicle-stimulating hormone receptor in the ovary, and the kisspeptin system were upregulated in the gonads of PNX-20 injected fish. We also observed the upregulation of genes involved in the sex steroidogenic pathway (cyp11a1, cyp17a1, 17βhsd, cyp19a1a) in the gonads of PNX-20 administered fish. PNX-20 upregulates the expression of vitellogenin isoforms and estrogen receptor (esr2a and 2b) mRNAs in ZFL cells in vitro. Meanwhile, siRNA-mediated knockdown of PNX-20 resulted in the downregulation of all vitellogenin transcripts, further suggesting its possible role in vitellogenesis. PNX-20 treatment resulted in a significant increase in germinal vesicle breakdown in zebrafish follicles in vitro. Collectively, these results provide strong evidence for PNX-20 effects on the HPG axis and liver to promote reproduction in zebrafish.

Hypothalamic- and pituitary-derived growth and reproductive hormones and the control of energy balance in fish

Most endocrine systems in the body are influenced by the hypothalamic-pituitary axis. Within this axis, the hypothalamus delivers precise signals to the pituitary gland, which in turn releases hormones that directly affect target tissues including the liver, thyroid gland, adrenal glands and gonads. This action modulates the release of additional hormones from the sites of action, regulating key physiological processes, including growth, metabolism, stress and reproduction. Pituitary hormones are released by five distinct hormone-producing cell types: somatotropes (which produce growth hormone), thyrotropes (thyrotropin), corticotropes (adrenocorticotropin), lactotropes (prolactin) and gonadotropes (follicle stimulating hormone and luteinizing hormone), each modulated by specific hypothalamic signals. This careful and distinct organization of the hypothalamo-pituitary axis has been classically associated with the existence of many lineal axes (e.g., the hypothalamic-pituitary-gonadal axis) in charge of the control of the different physiological processes. While this traditional concept is valid, it is becoming apparent that hormones produced by the hypothalamo-pituitary axis have diverse effects. For instance, gonadotropin-releasing hormone II has been associated with a suppressive effect on food intake in fish. Likewise, growth hormone has been shown to influence appetite, swimming activity and aggressive behavior in fish. This review will focus on the hypothalamic and pituitary hormones classically involved in regulating growth and reproduction, and will attempt to provide a general overview of the current knowledge on their actions on energy balance and appetite in fish. It will also give a brief perspective of the role of some of these peptides in integrating feeding, metabolism, growth and reproduction.

Does nesfatin-1 influence the hypothalamic–pituitary–gonadal axis in adult males with obstructive sleep apnoea?

There is growing evidence that obstructive sleep apnoea (OSA) influences the hypothalamic–pituitary–gonadal axis (HPG axis) in men. The aim of the study was to assess the association of nesfatin-1 with HPG axis disturbances in OSA. This is a prospective study with consecutive enrolment. It comprises 72 newly diagnosed OSA patients ((AHI: apnoea-hypopnea index) 18 subjects: 5 ≤ AHI < 15; 24: 15 ≤ AHI < 30; 30: AHI ≥ 30) and a control group composed of 19 patients (AHI < 5). All patients underwent polysomnography and fasting blood collection for nesfatin-1, testosterone, luteinising hormone (LH), high-sensitivity C-reactive protein (hsCRP), aspartate transaminase (AST), alanine aminotransferase (ALT), creatinine and glucose. Groups had similar levels of LH, nesfatin-1 and testosterone (p = 0.87; p = 0.24; p = 0.08). Nesfatin-1 was not correlated to LH (p = 0.71), testosterone (p = 0.38), AHI (p = 0.34) or the oxygen desaturation index (ODI) (p = 0.69) either in the whole group, or in sub-groups. The study did not reveal any association between the HPG axis and nesfatin-1 in OSA adult males. It is possible that nesfatin-1 is not a mediator of HPG axis disturbances in adult patients with OSA.

Nesfatin-1 regulates glucoregulatory genes in rainbow trout (Oncorhynchus mykiss)

The aim of this work was to determine if the anorexigen nesfatin-1 modulates the expression of genes involved in glucoregulation in rainbow trout. First, the nesfatin-1 sequence from trout was confirmed. Second, the effects of 0.1, 1 and 10 nM nesfatin-1 on insulin, glucagon, igf-I, igf-II, glut1, glut2, glut4 and sglt1 expression were tested in cultured liver, gut, muscle and adipose tissue. In liver, the expression of insulin and glucagon isoforms X1 increased after 2 h of incubation with 0.1 nM nesfatin-1, while insulin and glucagon X2 expression increased after 4 h with 1 nM treatment. All nesfatin-1 doses tested decreased glut2 expression after 4 h. In adipose tissue, all nesfatin-1 concentrations reduced insulin X1 expression at 30 min, and 1 nM nesfatin-1 increased insulin X2 expression at 4 h. In gut, 0.1, 1 and 10 nM nesfatin-1 decreased glut2 and sglt1 mRNA levels after 240 min of incubation. In muscle, 0.1 nM nesfatin-1 increased the expression of igf-I after 240 min. The expression of igf-II in muscle increased after 30 min of incubation with 1 and 10 nM nesfatin-1 and after 120 min of incubation with 0.1 and 1 nM nesfatin-1. Expression of glut1 and sglt1 in muscle increased after 240 min of incubation with 0.1 nM nesfatin-1 and after 120 min with 0.1 and 10 nM nesfatin-1, respectively. These results suggest that nesfatin-1 could decrease the gut intake of dietary glucose, and increase its uptake in glucoregulatory tissues such as liver and muscle of rainbow trout.

Metabolic hormones and the regulation of spermatogenesis in fishes

Metabolic hormones play essential regulatory roles in many biological processes, including morphogenesis, growth, and reproduction through the maintenance of energy balance. Various metabolic hormones originally discovered in mammals, including ghrelin, leptin, and nesfatin-1 have been identified and characterized in fish. However, physiological roles of these metabolic hormones in regulating reproduction are largely unknown in fishes, especially in males. While the information available is restricted, this review attempts to summarize the main findings on the roles of metabolic peptides on the reproductive system in male fishes with an emphasis on testicular development and spermatogenesis. Specifically, the primary goal is to review the physiological interactions between hormones that regulate reproduction and hormones that regulate metabolism as a critical determinant of testicular function. A brief introduction to the localization of metabolic hormones in fish testis is also provided. Besides, the consequences of fasting and food deprivation on testicular development and sperm quality will be discussed with a focus on interactions between metabolic and reproductive hormones.

Current Understanding of the Role of Nesfatin-1

Nesfatin-1 was discovered in 2006 and implicated in the regulation of food intake. Subsequently, its widespread central and peripheral distribution gave rise to additional effects. Indeed, a multitude of actions were described, including modulation of gastrointestinal functions, glucose and lipid metabolism, thermogenesis, mediation of anxiety and depression, as well as cardiovascular and reproductive functions. Recent years have witnessed a great increase in our knowledge of these effects and their underlying mechanisms, which will be discussed in the present review. Lastly, gaps in knowledge will be highlighted to foster further studies.

Serum Nesfatin-1 Levels in Girls with Idiopathic Central Precocious Puberty

OBJECTIVE

Nesfatin-1, an anorexigenic neuropeptide, is expressed mainly in the central nervous system and in some peripheral tissues. The role of nesfatin-1 in energy balance has been investigated. Despite the suggestion of a role for nesfatin-1 in reproductive function, data are limited on the role of nesfatin-1 in human puberty.

METHODS

The aim of this study was to investigate the following: i) the role of nesfatin-1 in puberty, and ii) relationship between nesfatin-1 and anthropometric measurements and gonadotropin levels in girls with idiopathic central precocious puberty (CPP). Twenty-four girls with CPP (7.68±1.02 years) and 20 female, prepubertal, healthy controls (7.48±0.88 years) were enrolled in the study. All patients with CPP were treated by the intramuscular administration of leuprolide acetate at a daily dose of 3.75 mg for 28 days. Nesfatin-1 was measured before and during treatment.

RESULTS

There was no difference in serum nesfatin-1 levels in girls with CPP and healthy controls [5.67 (2.5-20.6) mmol/L and 5.75 (2.51-9.64) mmol/L], respectively. There was a negative correlation between nesfatin-1 levels and body weight and body mass index-standard deviation score (p=0.01, r=-0.83; p=0.025, r=-0.81, respectively). No correlation was found between nesfatin-1 and gonadotropin, estradiol levels, uterine length or endometrial thickness.

CONCLUSION

The results of this study suggest that there are no differences between girls with CPP and healthy, prepubertal girls regarding nesfatin-1 levels.

The role of nesfatin-1 expression in letrozole-induced polycystic ovaries in the rat

Polycystic ovary syndrome (PCOS) is a complex and heterogeneous endocrine disorder, generally exhibiting the characteristic features of hyperandrogenemia, insulin resistance (IR) and obesity. Nesfatin-1 is derived from the precursor nucleobindin2 (NUCB2), and plays an active role in energy balance, glucose metabolism and most likely gonadal function. In order to explore the role of nesfatin-1, we employed a rat model that uses letrozole to induce PCOS. The PCOS rats exhibited increased body weight, irregular cycles, polycystic ovaries characterized by cysts formed from atretic follicles, and a diminished granulosa layer. The expression of both nesfatin-1 mRNA and protein in the ovarian tissues of PCOS group decreased significantly compared to the control group (p < 0.05). Nesfatin-1 expression in peripheral blood also decreased in the PCOS group, in contrast with the control group. Furthermore, we found that nesfatin-1 had a positive correlation with FSH, E₂ and P, whereas it had a negative correlation with LH, and total T (p < 0.05). When taken together, these data indicated that the decrease in nesfatin-1 may contribute to the mechanism governing PCOS, and might provide a new potential target for therapies aimed at treating PCOS.

Serum Cytokine Levels are related to Nesfatin-1/NUCB2 Expression in the Implantation Sites of Spontaneous Abortion Model of CBA/j × DBA/2 Mice

The process of spontaneous abortion involves a complex mechanism with various cytokines, growth factors, and hormones during the pregnancy. However, the mechanism underlying spontaneous abortion by pro- and anti-inflammatory cytokines in the serum during the pregnancy is not fully understood. Therefore, the purpose of this study was to examine the relationship between the serum levels of pro- and anti-inflammatory cytokines and spontaneous abortion using the CBA/j × DBA/2 mouse model. Serum levels of pro-inflammatory cytokines, such as IFN-γ, IL-1α and TNF-α were not increased in abortion model mice, but anti-inflammatory cytokines, such as IL-4, IL-13 and IL-1ra were decreased compared to normal pregnant mice. In addition, serum levels of chemokine, such as SDF-1, G-CSF, M-CSF, IL-16, KC and MCP-1 were decreased in abortion model mice compared to normal pregnant mice. However, the expression levels of nesfatin-1/NUCB2 mRNA and protein in the uteri of implantation sites were significantly higher in abortion model mice than normal pregnant mice. These results suggest that uterine nesfatin-1/NUCB2 expression may be down-regulated by inflammatory cytokines and chemokines in the serum of pregnant mice. Moreover, this study suggests the possibility that nesfatin-1/NUCB2 expressed in the implantation sites may be associated with the maintenance of pregnancy.

Nesfatin-1: functions and physiology of a novel regulatory peptide

Nesfatin-1 was identified in 2006 as a potent anorexigenic peptide involved in the regulation of homeostatic feeding. It is processed from the precursor-peptide NEFA/nucleobindin 2 (NUCB2), which is expressed both in the central nervous system as well as in the periphery, from where it can access the brain via non-saturable transmembrane diffusion. In hypothalamus and brainstem, nesfatin-1 recruits the oxytocin, the melancortin and other systems to relay its anorexigenic properties. NUCB2/nesfatin-1 peptide expression in reward-related areas suggests that nesfatin-1 might also be involved in hedonic feeding. Besides its initially discovered anorexigenic properties, over the last years, other important functions of nesfatin-1 have been discovered, many of them related to energy homeostasis, e.g. energy expenditure and glucose homeostasis. Nesfatin-1 is not only affecting these physiological processes but also the alterations of the metabolic state (e.g. fat mass, glycemic state) have an impact on the synthesis and release of NUCB2 and/or nesfatin-1. Furthermore, nesfatin-1 exerts pleiotropic actions at the level of cardiovascular and digestive systems, as well as plays a role in stress response, behavior, sleep and reproduction. Despite the recent advances in nesfatin-1 research, a putative receptor has not been identified and furthermore potentially distinct functions of nesfatin-1 and its precursor NUCB2 have not been dissected yet. To tackle these open questions will be the major objectives of future research to broaden our knowledge on NUCB2/nesfatin-1.

Role of Nesfatin-1 in the Reproductive Axis of Male Rat

Nesfatin-1 is an important molecule in the regulation of reproduction. However, its role in the reproductive axis in male animals remains to be understood. Here, we found that nesfatin-1 was mainly distributed in the arcuate nucleus (ARC), paraventricular nucleus (PVN), periventricular nucleus (PeN), and lateral hypothalamic area (LHA) of the hypothalamus; adenohypophysis and Leydig cells in male rats. Moreover, the concentrations of serum nesfatin-1 and its mRNA in hypothalamo-pituitary-gonadal axis (HPGA) vary with the age of the male rat. After intracerebroventricular injection of nesfatin-1, the hypothalamic genes for gonadotrophin releasing hormone (GnRH), kisspeptin (Kiss-1), pituitary genes for follicle-stimulate hormone β(FSHβ), luteinizing hormone β(LHβ), and genes for testicular steroidogenic acute regulatory (StAR) expression levels were decreased significantly. Nesfatin-1 significantly increased the expression of genes for 3β-hydroxysteroid dehydrogenase (3β-HSD), 17β-hydroxysteroid dehydrogenase (17β-HSD), and cytochrome P450 cleavage (P450scc) in the testis of pubertal rats, but their levels decreased in adult rats (P < 0.05), along with the serum FSH, LH, and testosterone (T) concentrations. After nesfatin-1 addition in vitro, T concentrations of the supernatant were significantly higher than that in the control group. These results were suggestive of the role of nesfatin-1 in the regulation of the reproductive axis in male rats.

Nesfatin-1: current status as a peripheral hormone and future prospects

This review summarizes current data focusing on the peripheral effects of NUCB2/nesfatin-1 including the regulation of food intake, glucose homeostasis, lipid metabolism, cardiovascular effects and reproductive functions as well as its possible involvement in psychological disorders. Additionally, we will highlight gaps in knowledge in order to stimulate further research. Lastly, we will give an outlook on potential therapeutic implications of this pleiotropic peptide.

Ultrasonography reveals in vivo dose-dependent inhibition of end systolic and diastolic volumes, heart rate and cardiac output by nesfatin-1 in zebrafish

Nesfatin-1 is an 82 amino acid peptide that inhibits food intake in rodents and fish. While endogenous nesfatin-1, and its role in the regulation of food intake and hormone secretion has been reported in fish, information on cardiovascular functions of nesfatin-1 in fish is in its infancy. We hypothesized that cardiac NUCB2 expression is meal responsive and nesfatin-1 is a cardioregulatory peptide in zebrafish. NUCB2/nesfatin-1 like immunoreactivity was detected in zebrafish cardiomyocytes. Real-time quantitative PCR analysis found that the cardiac expression of NUCB2A mRNA in unfed fish decreased at 1h post-regular feeding time. Food deprivation for 7days did not change NUCB2A mRNA expression. However, NUCB2B mRNA expression was increased in the heart of zebrafish after a 7-day food deprivation. Ultrasonography of zebrafish heart at 15min post-intraperitoneal injection of nesfatin-1 (250 and 500ng/g body weight) showed a dose-dependent inhibition of end diastolic and end systolic volumes. A dose dependent decrease in heart rate and cardiac output was observed in zebrafish that received nesfatin-1, but no changes in stroke volume were found. Nesfatin-1 treatment caused a significant increase in the expression of Atp2a2a mRNA encoding the calcium-handling pump, SERCA2a, while it had no effects on the expression of calcium handling protein RyR1b encoding mRNA. Our data support cardiosuppressive effects of nesfatin-1 in zebrafish, and reveals energy availability as one determinant of cardiac NUCB2 mRNA expression.

Nesfatin-1-Like Peptide Encoded in Nucleobindin-1 in Goldfish is a Novel Anorexigen Modulated by Sex Steroids, Macronutrients and Daily Rhythm

Nesfatin-1 is an 82 amino acid anorexigen encoded in a secreted precursor nucleobindin-2 (NUCB2). NUCB2 was named so due to its high sequence similarity with nucleobindin-1 (NUCB1). It was recently reported that NUCB1 encodes an insulinotropic nesfatin-1-like peptide (NLP) in mice. Here, we aimed to characterize NLP in fish. RT- qPCR showed NUCB1 expression in both central and peripheral tissues. Western blot analysis and/or fluorescence immunohistochemistry determined NUCB1/NLP in the brain, pituitary, testis, ovary and gut of goldfish. NUCB1 mRNA expression in goldfish pituitary and gut displayed a daily rhythmic pattern of expression. Pituitary NUCB1 mRNA expression was downregulated by estradiol, while testosterone upregulated its expression in female goldfish brain. High carbohydrate and fat suppressed NUCB1 mRNA expression in the brain and gut. Intraperitoneal injection of synthetic rat NLP and goldfish NLP at 10 and 100 ng/g body weight doses caused potent inhibition of food intake in goldfish. NLP injection also downregulated the expression of mRNAs encoding orexigens, preproghrelin and orexin-A, and upregulated anorexigen cocaine and amphetamine regulated transcript mRNA in goldfish brain. Collectively, these results provide the first set of results supporting the anorectic action of NLP, and the regulation of tissue specific expression of goldfish NUCB1.

Nesfatin-1: a new energy-regulating peptide with pleiotropic functions. Implications at cardiovascular level

Nesfatin-1 is a new energy-regulating peptide widely expressed at both central and peripheral tissues with pleiotropic effects. In the last years, the study of nesfatin-1 actions and its possible implication in the development of different diseases has created a great interest among the scientific community. In this review, we will summarize nesfatin-1 main functions, focusing on its cardiovascular implications.

Estradiol and testosterone modulate the tissue-specific expression of ghrelin, ghs-r, goat and nucb2 in goldfish

Ghrelin, and nesfatin-1 (encoded by nucleobindin2/nucb2) are two metabolic peptides with multiple biological effects in vertebrates. While sex steroids are known to regulate endogenous ghrelin and NUCB2 in mammals, such actions by steroids in fish remain unknown. This study aimed to determine whether estradiol (E2) and testosterone (T) affects the expression of preproghrelin, ghrelin/growth hormone secretagogue receptor (GHS-R), ghrelin O-acyl transferase (GOAT) and NUCB2 in goldfish (Carassius auratus). First, a dose-response assay was performed in which fish were intraperitoneally (ip) implanted with pellets containing 25, 50 or 100 μg/g body weight (BW) of E2 or T. It was found that sex steroids (100 μg/g BW) administered for 2.5 days achieved the highest E2 or T in circulation. In a second experiment, fish were ip implanted with pellets containing 100 μg/g BW of E2, T or without hormone (control). RT-qPCR analyses at 2.5 days post-administration show that gut preproghrelin and GOAT expression was upregulated by both E2 and T treatments, while the same effect was observed for GHS-R only in the pituitary. Both treatments also reduced hypothalamic preproghrelin mRNA expression. NUCB2 expression was increased in the forebrain of T treated group and reduced in the gut and pituitary under both treatments. These results show for the first time a modulation of preproghrelin and nucb2/nesfatin-1 by sex steroids in fish. The interaction between sex steroids and genes implicated in both metabolism and reproduction might help meeting the reproduction dependent energy demands in fish.

Nesfatin-1 stimulates cholecystokinin and suppresses peptide YY expression and secretion in mice

Nesfatin-1 is an 82 amino acid secreted peptide encoded in the precursor, nucleobindin-2 (NUCB2). It is an insulinotropic anorexigen abundantly expressed in the stomach and hypothalamus. Post-prandial insulin secretion is predominantly regulated by incretins glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP). Nesfatin-1 was previously reported to modulate GLP-1 and GIP secretion in vitro in an enteroendocrine (STC-1) cell line. Intestine is a source of additional hormones including cholecystokinin (CCK) and peptide YY (PYY) that regulate metabolism. We hypothesized that nesfatin-1 modulates CCK and PYY secretion. Immunofluorescence histochemistry showed NUCB2/nesfatin-1 co-localizing CCK and PYY in the intestinal mucosa of mice. Static incubation of STC-1 cells with nesfatin-1 upregulated both CCK mRNA expression (1 and 10 nM) and secretion (0.1, 1 and 10 nM) at 1 h post-incubation. In contrast, nesfatin-1 treatment for 1 h downregulated PYY mRNA expression (all doses tested) and secretion (0.01 and 0.1 nM) in STC-1 cells. Continuous infusion of nesfatin-1 using osmotic mini-pumps for 12 h upregulated CCK mRNA expression in large intestine, and downregulated PYY mRNA expression in both large and small intestines of male C57BL/6J mice. In these tissues, Western blot analysis found a corresponding increase in CCK and a decrease in PYY content. Collectively, we provide new information on the cell specific localization of NUCB2/nesfatin-1 in the intestinal mucosa, and a novel function for nesfatin-1 in modulating intestinal CCK and PYY expression and secretion in mice.

Tissue-specific expression of ghrelinergic and NUCB2/nesfatin-1 systems in goldfish (Carassius auratus) is modulated by macronutrient composition of diets

The macronutrient composition of diets is a very important factor in the regulation of body weight and metabolism. Several lines of research in mammals have shown that macronutrients differentially regulate metabolic hormones, including ghrelin and nesfatin-1 that have opposing effects on energy balance. This study aimed to determine whether macronutrients modulate the expression of ghrelin and the nucleobindin-2 (NUCB2) encoded nesfatin-1 in goldfish (Carassius auratus). Fish were fed once daily on control, high-carbohydrate, high-protein, high-fat and very high-fat diets for 7 (short-term) or 28 (long-term) days. The expression of preproghrelin, ghrelin O-acyl transferase (goat), growth hormone secretagogue receptor 1 (ghs-r1) and nucb2/nesfatin-1 mRNAs was quantified in the hypothalamus, pituitary, gut and liver. Short-term feeding with fat-enriched diets significantly increased nucb2 mRNA levels in hypothalamus and liver, preproghrelin, goat and ghs-r1 expression in pituitary, and ghs-r1 expression in gut. Fish fed on a high-protein diet exhibited a significant reduction in preproghrelin and ghs-r1 mRNAs in the liver. After long-term feeding, fish fed on high-carbohydrate and very high-fat diets had significantly increased preproghrelin, goat and ghs-r1 expression in pituitary. Feeding on a high-carbohydrate diet also upregulated goat and ghs-r1 transcripts in gut, while feeding on a high-fat diet elicited the same effect only for ghs-r1 in liver. Nucb2 expression increased in pituitary, while it decreased in gut after long-term feeding of a high-protein diet. Collectively, these results show for the first time in fish that macronutrients differentially regulate the expression of ghrelinergic and NUCB2/nesfatin-1 systems in central and peripheral tissues of goldfish.

Th 17 Cells and Nesfatin-1 are associated with Spontaneous Abortion in the CBA/j × DBA/2 Mouse Model

The pregnancy and abortion process involves a complex mechanism with various immune cells present in the implantation sites and several hormones associated with pregnancy, such as leptin, ghrelin and nesfatin-1. However, the mechanism underlying spontaneous abortion by maternal T helper 17 (Th17) present in the implantation sites and nesfatin-1, which is of anorexigenic hormones, is not fully understood so far. Therefore, the purpose of this study was to examine the possible roles of Th17 cells present in the implantation sites and nesfatin-1 expressed in the uterus on spontaneous abortion using the CBA/j × DBA/2 mouse model. Th17 transcription factor, ROR-γt mRNA expression was significantly increased in the abortion sites compared with the implantation sites of abortion model mice on day 14.5 and 19.5 of pregnancy. In addition, the expression levels of IL(-1)7A mRNA were significantly higher in abortion sites than in implantation sites on day 14.5 and 19.5. Moreover, the nesfatin-1/NUCB2 protein and mRNA levels were increased in abortion sites compared with levels in implantation sites of both normal pregnant and abortion model mice on day 14.5 of pregnancy. Interestingly, nesfatin- 1/NUCB2 serum levels were not changed throughout the whole pregnancy in abortion model mice, but its serum level was dramatically increased on day 14.5, and then rapidly decreased on day 19.5 in normal pregnant mice. In this study, we showed for the first time the expression of nesfatin-1/NUCB2 mRNA and protein in implantation sites during pregnancy. The present results suggest that Th17 cells in the uterus may play an important role in the period of implantation and for maintenance of pregnancy. Furthermore, the present results suggest that Th17 cells in implantation sites may be a key regulator for maintenance of pregnancy and provides evidence that activation of these cells may be regulated by nesfatin-1/NUCB2. Further study is needed to elucidate the role of nesfatin-1 expressed in the uterus during pregnancy.

Nesfatin-1: Localization and expression in avian gonads and its modulation by temporal phase relation of neural oscillations in female Japanese quail, Coturnix coturnix japonica

In a search for new appetite-controlling signals, the peptide nesfatin-1, expressed in the brain and peripheral tissues of rodents and humans has been reported to regulate feeding by reducing food intake. Recently it has also been reported that nesfatin-1 might be involved in regulating the reproductive axis in fishes and mammals, but its expression and physiological role if any, is not yet known in birds. In the present study, localization and expression of nesfatin-1 was observed in the testis, ovary and shell gland of poultry species Japanese quail, Coturnix coturnix japonica. Our earlier studies have reported that serotonin precursor 5-HTP and dopamine precursor l-DOPA given 8h apart induces gonadal suppression, when given 12h apart leads to gonadal stimulation while other relationships were found ineffective. In the present study intense ir-nesfatin-1 was observed in the regressed ovary (stromal cells) and shell gland (endometrium) of 8-h Japanese quail while in 12-h quail, weak and scarce immunostaining for nesfatin-1 was detected in the hyperactive ovary and shell gland compared to control. These findings led us to conclude that, an inverse relationship exists between ovarian activity (both in the control and simulated conditions) and nesfatin-1 expression. Present avian study, first of its kind, also suggests the role of nesfatin-1 in reproductive regulation possibly via appetite control and energy balance in female Japanese quail and needs to be investigated further in relation to food intake.